Apparatus for transmitting power.



J. DUNLOP.

APPARATUS FOR TRANSMITTING POWER.

APIPLIOATION FILED JULY 6, 1910.

989,583. Patented Apr. 18, 1911.

JAMES DUNLOP, 0F DENNISTOUN, GLASGOW, SCOTLAND.

APPARATUS FOR TRANSMITTING POWER.

Specification of Letters Patent.

Patented Apr. 18, 1911.

Application filed July 5, 1910. Serial No. 570,290.

To all whom it may concern:

Be it known that I, JAMns DUNLOP, a sub ject of the King of the UnitedKingdom of Great Britain and Ireland, and residing at Dennistoun,Glasgow, Scotland, have invented a certain new and useful Improvement inApparatus for Transmitting Power, of which the following is aspecification.

This invention relates to two pipe, dense air or closed circuit systemsfor transmitting power by compressed air.

The system shown and descrlbed in Letters Patent of the United StatesNo. 965,285, granted to me July 26, 19-10, comprises, in general, an aircompressor driven by a suitable engine, a compressed air motor, a.delivery pipe for conveying compressed air from the compressor to themotor, and a return pipe for reconveying the air from the exhaust of themotor to the compressor. In said system a hand operated isolating valveis provided at the inlet of the air compressor so that the return pipeof the system may be isolated from the air compressor, and a handoperated atmospheric valve is provided at the inlet of the aircompressor so that the inlet of the air compressor may be put incommunication with the atmosphere when it is required to charge thesystem.

The primary object of this invention is to make the isolating valve orvalves and the atmospheric valve or valves automatic in their movementsso that the pressure and quantity of air maintained in the system willbe controlled and provided for without any necessity for the use of asupplementary air compressor, or, if a supplementary air compressor beused, without any necessity for the use of any other apparatus than theautomatic isolating and atmospheric valves to control both the main andthe supplementary air compressors, the movements of the automaticisolating and atmospheric valves being such that the system may beoperated as a variable pressure system or as a constant pressure systemas required.

A further object is to control the move ments of the isolating andatmospheric valves so that when a multiple cylinder air compressor isused the pressure and quantity of air circulated in the system may beregulated to suit the power and speed of the air engine without the useof valve actuating mechanism for the air compressor.

In the accompanying drawings, Figure 1 shows diagrammatically part of aclosed circuit air-transmission system equipped with isolating andatmospheric valves adapted to operate in accordance with the invention.Fig. 2 shows a modified construction of pilot valve. Fig. 3 showsdiagrammat-ically a modification hereinafter re-- ferred to.

Referring to the drawings, I prefer to employ an isolating valve A ofthe equilibrium type provided with a piston B sliding in a cylinder Othe arrangement being such that one side Z) of the piston is at alltimes exposed to the pressure in the return plpe D of the system, whilethe other side I) of the piston is exposed alternately to the pressurein the return pipe of the system, through the branches (Z, cl, and tothe atmosphere through the branch (Z and the outlet (i This alternationof pressure is determined by a weighted or spring loaded pilot valve Eso arranged that until the desired pressure to be maintained in thesystem is attained both sides of the isolating valve piston B will beexposed to the pressure in the return pipe D of the system so that theisolating valve A will be kept closed, and when the desired pressure isattained the movement of the pilot valve E under that pressure withinthe branch (Z will establish communication between the atmosphere at dand the side 6' of the isolating valve piston B, thus putting it out ofbalance and so causing the isolating valve A to open.

The atmospheric valve F is preferably of the ordinary lift type and isprovided with a piston G sliding in a cylinder H the arrangement beingsuch that one side 9 of the piston G is at all times exposed to thepressure in the inlet pipe I of the air compressor J while the otherside 9 of the piston G is exposed alternately. to the pressure in theinlet pipe I of the air compressor, through the branches '5, i, and tothe pressure in the delivery pipe K of the system through the inlet 2'and the branch 2". This alternation of pressure is determined by theweighted or spring loaded pilot valve E which at such times as itestablishes communication between the atmosphere at d and the side 6 ofthe isolating valve piston B will also expose the side g of theatmospheric valve piston G to the pressure in the delivery pipe K of thesystem, the atmospheric valve F being thus closed. at such times as theisolating valve A is opened and vice versa. The pilot valve E ispreferably constructed in the form of a plunger of two diameters slidingin a cylinder 0 provided with suitable ports the plunger being providedwith suitable grooves to control the alternations of pressure abovedescribed. The smaller and the annular areas of the plunger are madeequal so that with the delivery and return pipes of equal capacity thesum of the pressures acting on the plunger will be a constant no matterwhat diiterence exists between the pressures in the delivery and returnpipes K, D, of the system respectively. The delivery pipe pressure mayact on the smaller area and the return pipe pressure on the annular areaor vice versa provided the ports and grooves are arranged to suit.

As shown in Fig. 2, instead of being of two diameters, the pilot valvemay be arranged with two separate plungers E each within a cylinder 6and each provided with a weight or a spring 6 the springs, when such areused, being of equal range under equal pressures and arranged to abut ona double armed lever L or the equivalent, so that on release of onespring 6 and compression of the other spring 6 the pilot valves E willno longer move in unison but will move at such times that the isolatingvalve A will open and close so as to maintain any desired difference ofpressure between the delivery and return pipes of the system and theatmospheric valve F will open and close so as to maintain the quantityof air in the system. From this it will be seen that when asupplementary air compressor is used for the purpose of making upleakage the isolating valve may be placed at the inlet of the main aircompressor and the atmospheric valve at the inlet of the supplementaryair compressor and that the system will operate as a constant pressuresystem without any other apparatus being used to control the system.

Referring to Fig. 3, this construction of pilot valve will permitmultiple cylinder air compressors to operate variable power and speedair engines without the necessity for the use of valve actuatingmechanism for the compressor inlet and delivery valves j, j, if any ofthe well known devices for holding open the delivery (or the inlet)valves of the compressor be arranged to be hand operated so that one orany other number of compressors may be brought into action as required.As shown, the delivery valve y" of each compressor is adapted to becontrolled by a hand operated regulating valve M located within a casingm which is connected to the delivery pipe K by a branch m and isconnected by branches m to the valve chests j of the air compressors:the arrangement is such that one or more of the air compressors may bebrought into action when the valve M is moved to permit communicationbetween one or more of the delivery valves j and the delivery pipe K,through the intermediary of the branches m, 911?, but when said valve Mis moved so as to permit communication between one or more of thedelivery valves 7' and a branch m leading to the atmosphere, said valvesj and the corresponding number of air compressors are thrown out ofaction. In the case of the inlet valves pressure is used to lift these'alves from their seats and so put the compressor out of action and theremoval of the pressure brings the compressor again into action. Theinlet pipe I has branches I. leading to the valve chests j which chestshave also branches 76 leading to the delivery pipe K. D is the returnpipe. A is the isolating valve and F is the atmospheric valve.

It will thus be understood that the system operates partially as avariable pressure system and partially as a constant pressure systemmore or less according to the number of air compressor cylinders inaction and to the power and speed required of the air engine.

lVhat I claim is 1. In a closed circuit system for transmitting power bycompressed air, the combination of an air compressor, an isolating valveand an atmospheric valve in said circuit, and pilot valve elementsautomatically controlled by the pressure in said system for controllingthe opening and closing of said isolating and atmospheric valves.

2. In a closed circuit system for transmitting power by compressed air,the combination of an air compressor, return and delivery pipes leadingto and from said air compressor respectively, isolating and atmosphericvalves in said return pipe, and means whereby the opening and closing ofsaid valves is automatically controlled by the pressure in said deliverypipe.

- 3. I11 a closed circuit system for transmitting power by compressedair, the combination of an air compressor, return and delivery pipesleading to and from said air compressor respectively, isolating andatmospheric valves in said return pipe, and pilot valve elementsautomatically controlled by the pressure in said delivery pipe forcontrolling the opening and closing of said isolating and atmosphericvalves.

4:. In a closed circuit system for transmitting power by compressed air,the combination of a multiple cylinder air compressor, inlet anddelivery valves for the respective cylinders of said compressor, anisolating valve and an atmospheric valve in said circuit, pilot valveelements automatically controlled by the pressure in said system forcontrolling the opening and closing of said isolating and atmosphericvalves, and means for controlling the opening and closing of one of thevalves of each of said compressor cylinders.

5. In a closed circuit system for transmitting power by compressed air,the combination of a multiple cylinder air compressor, inlet anddelivery valves for the respective cylinders of said compressor, anisolatin valve and an atmospheric valve in sald circuit, pilot valveelements automatically controlled by the pressure in said system forcontrolling the opening and closing of said isolating and atmosphericvalves, a fluid conduit communicating with. one of the valves of each ofsaid compressor cylinders, the openin and closing movements of saidlast-name valves being controlled by fluid pressure in said conduits,and a valve for controlling said conduits.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES DUNLOP.

Witnesses WALLACE CRANSTON FAIRWEA'LHER, J OHN MOCLEARY, Jr.

Copies of this patent may be obtained for five cents each, byaddressingthe Commissioner of Patents, Washington, I). G.

